ReinDB launches read-only PostgreSQL performance monitoring with query drift detection

Bandlei has released ReinDB, a read-only performance monitoring tool for PostgreSQL that works with self-managed instances as well as Amazon RDS and Aurora. The service learns normal behavior patterns for each database and individual statement on an hourly basis using the pg_stat_statements extension, then identifies and ranks deviations by the additional database time they consume.

Each detected anomaly includes supporting evidence such as execution plan history, along with a testable fix script and corresponding undo operation for each remediation step. ReinDB requires only a single read-only login and installs no components within the target database. Deployment options include hosted service, on-premises Linux or Windows installations, or customer-managed AWS and Google Cloud accounts. The offering also supports MySQL, SQL Server, and Oracle. A single database is available free for one user without time limits or payment card requirements, and Bandlei publishes a 109-page guide titled "Rein In Your Database" documenting the underlying tuning methodology.

How ReinDB monitors without invasive installation

• pg_stat_statements dependency: ReinDB relies on PostgreSQL's built-in pg_stat_statements extension to collect query execution statistics, using this data to build hourly baselines for each statement rather than deploying proprietary agents or schema changes.
• Read-only access model: The tool requires only a single read-only database login and installs nothing inside the monitored database, reducing security surface area and avoiding the performance overhead or maintenance burden of in-database instrumentation.
• Drift detection with cost ranking: Deviations from established baselines are flagged and ranked according to the additional database time they introduce, prioritizing issues by actual performance impact rather than simple threshold alerts.
• Evidence and remediation workflow: Each flagged issue includes plan history for root-cause analysis, plus generated fix scripts that DBAs can test in isolation with accompanying undo scripts for safe rollback.
• Multi-platform deployment: Beyond hosted SaaS, ReinDB runs on-premises on Linux or Windows, or within customer AWS and Google Cloud accounts, with support extending to MySQL, SQL Server, and Oracle in addition to PostgreSQL.

Why it matters

For PostgreSQL administrators managing production workloads on RDS, Aurora, or self-managed instances, ReinDB offers a monitoring approach that avoids the privilege escalation and maintenance complications common to agent-based tools. The read-only, zero-install architecture aligns with security-conscious deployment practices in regulated environments, while the ranked cost model helps DBAs prioritize tuning effort by measurable business impact rather than noise from static thresholds. The free tier for a single database lowers the barrier for individual developers and small teams to adopt systematic performance baselining.